‘757 Captain’ FLIGHT MANUAL Part V – Flight Management System (cs757_manual5.pdf) page 17:

MANUALLY ENTERED LATITUDE/ LONGITUDE WAYPOINTS

Pilot defined waypoints entered as a latitude and longitude are shown in a seven-character format. Latitude
and longitude waypoints are entered with no space or slash between the latitude and longitude entries.
Leading zeroes must be entered. All digits and decimal points (to 1/10 minute) must be entered unless the
latitude or longitude are full degrees. Examples:

· N47° W008° is entered as N47W008 and displays as N47W008
· N47° 15.4' W008° 3.4' is entered as N4715.4W00803.4 and displays as N47W008.

Hope this helps. ;)